Hi,

Thanks for the help, I do not seem to be able to run with that --debug=d,*:t:i  setup, it does not seem to progress. But, I attached a debugger to node0 mysqld and set up a breakpoint on savepoint set and rollback, I see at set:

#1  0x000000000086c981 in ha_savepoint (thd=0x41b9d40, sv=0x7f0ac4007328) at /home/jan/mysql/galera-10.0/sql/handler.cc:2065
(gdb) graph display *trans
(gdb)  p *sv
$4 = {prev = 0xa5a5a5a5a5a5a5a5, name = 0x7f0ac4007390 "A", length = 1, ha_list = 0xa5a5a5a5a5a5a5a5, mdl_savepoint = {m_stmt_ticket = 0xa5a5a5a5a5a5a5a5, m_trans_ticket = 0xa5a5a5a5a5a5a5a5}}

and in

static int binlog_savepoint_set(handlerton *hton, THD *thd, void *sv)
{
  DBUG_ENTER("binlog_savepoint_set");
  int error= 1;

  char buf[1024];
#ifdef WITH_WSREP
  if (wsrep_emulate_bin_log) DBUG_RETURN(0);
#endif /* WITH_WSREP */

wsrep_emulate_bin_log = 1, thus no savepoint is written to bin log

and continue in debugger we get

#1  0x000000000086c6fe in ha_rollback_to_savepoint (thd=0x47c7d40, sv=0x7fe364007328) at /home/jan/mysql/galera-10.0/sql/handler.cc:2009
(gdb) print *sv
$2 = {prev = 0x0, name = 0x7fe364007390 "A", length = 1, ha_list = 0x47c9ba0, mdl_savepoint = {m_stmt_ticket = 0x0, m_trans_ticket = 0x7fe36405b1e0}}

where mdl_savepoint.m_trans_ticket

(gdb) p *sv->mdl_savepoint.m_trans_ticket
$5 = {<MDL_wait_for_subgraph> = {_vptr.MDL_wait_for_subgraph = 0x16ce390 <vtable for MDL_ticket+16>}, next_in_context = 0x7fe36405aec0, prev_in_context = 0x47c7f30, next_in_lock = 0x0, prev_in_lock = 0x7fe364059298, m_type = MDL_SHARED_WRITE, m_duration = MDL_TRANSACTION, m_ctx = 0x47c7e38, m_lock = 0x4659000}
(gdb) p sv
$6 = (SAVEPOINT *) 0x7fe364007328
(gdb) p ht
$7 = (handlerton *) 0x3aa1fb0
(gdb) p ht->savepoint_offset

This I can't understand:

if ((err= ht->savepoint_rollback(ht, thd,
                                     (uchar *)(sv+1)+ht->savepoint_offset)))

there
(gdb) p ht->savepoint_offset
$8 = 0
and
$9 = (SAVEPOINT *) 0x7fe364007358
(gdb) p *(sv+1)
$10 = {prev = 0xa5a5a5a5a5a5a5a5, name = 0xa5a5a5a5a5a5a5a5 <Address 0xa5a5a5a5a5a5a5a5 out of bounds>, length = 2779096485, ha_list = 0xa5a5a5a5a5a5a5a5, mdl_savepoint = {m_stmt_ticket = 0xa5a5a5a5a5a5a5a5, m_trans_ticket = 0xa5a5a5a5a5a5a5a5}}